This is stating that it could not map port 50000 on the local machine, possibly because it was in use. I ran netstat to list all of the ports that were in use:

netstat -a -n -o

Nothing was using port 50000, something strange was going on.

I was able to start the VM removing the ‘-p 50000:50000’ but
I’ve assumed it needs to map this port in order to work correctly.

Coming back the following morning (after shutting down the
vm) all was resolved so perhaps a reboot was all it needed?

Ok so now I’ve run the command and my docker
container is running! (wahoo!!!)

Open a browser on the VM and go to: Http://localhost:8080

However, as I started the container removing the port 50000 mapping I don't have the administrator password to start Jenkins.

However, it states that it is available by browsing to /var/jenkins_home/secrets/initialAdminPassword

As I started the container previously the Admin password isn’t
now shown in the output when starting the container (it is only shown the first
time), so I now need to browse the local file system of the container to get
the password.

To do this I opened a new PowerShell window.

The Docker ps command lists the running containers and it also
lists the ‘name’ for it, which in my case is called dreamy_bhabha.